There is a trend toward less invasive surgical procedures performed by introducing small diameter, flexible tools into natural body openings and small incisions. These tools can enable tissue visualization, imaging, analysis, manipulation, cutting, coagulation, and removal. An example of a procedure done through a natural body opening is polyp visualization and removal during a colonoscopy. Examples of procedures done through one or more small incisions utilizing access devices such as trocars include laparascopic hysterectomy or cholecystectomy. Laparoscopic incisions are typically 3 mm to 15 mm in diameter. Some procedures can be done through incisions 3 mm or smaller, and have been called “needlescopic”.
One type of laparascopic surgery is single incision laparascopic surgery, where a multiport trocar is used to introduce a cluster of surgical tools. Incisions that start from an instrument already in a natural body opening, called natural orifice transluminal endoscopic surgery (“NOTES”), are a topic of current surgical research, as are various percutaneous procedures. Examples include NOTES cholicystectomy.
Referring to FIG. 1, traditional laparascopic tooling 100 typically includes a long, small diameter rigid shaft 110 with a working feature 120 located on the distal end, and a hand grip 130 located proximally. The shaft 110 is commonly stainless steel with an outer diameter D2 being an industry standard size, commonly 3 mm, 5 mm, or 8 mm.
Referring to FIG. 2, these specific laparascopic shaft sizes are desirable due to the need for the tool to pass through an opening of an access device such as a trocar 200 typically used in minimally invasive procedures and having a similar size. For example, trocars with inner diameter openings D3 of approximately 4 mm, 6 mm, and 9 mm may be used with 3 mm, 5 mm, and 8 mm tools, respectively. A laparascopic trocar 200 typically includes a sleeve or cannula 210 and a sealing orifice within a seal housing 220. The seal housing 220 typically includes a relief valve 230, also utilized for insufflation gases. Sealing orifices are designed to maintain pressure in the abdomen during laparascopic surgery, and may also utilize a duckbill type of elastomeric check valve, in which pressure on the high pressure side of the seal helps maintain closure.
Trocar sleeve lengths vary, with typical lengths ranging from 7 cm to 15 cm. The term “trocar” is utilized broadly herein to include a tubular cannula or sleeve with proximal seal housing through which sharp-tipped or blunt instruments are insertable, such as disclosed in the following U.S. Pat. Nos. 5,385,553; 5,792,112; 5,803,919; and 6,217,555 by Hart et al.
Long, thin, flexible waveguides are well adapted for performing the procedures described above, and suit the current growing interest in and use of laser surgery. Generally, waveguides may be strengthened and protected by additional elements on the outside, such as jackets, and may have additional elements that add functionality, such as distal tips. Waveguides disposed inside protective jackets and having additional functionality elements are often referred to as waveguide assemblies.
For further mechanical strength and manipulation, it may be desirable to place waveguides or waveguide assemblies inside other mechanical structures, e.g., waveguide conduits, which may provide protection, strength, and structure for surgical access control.
Waveguide conduits are typically placed on waveguides or waveguide assemblies after manufacturing or assembly of the waveguides, generally at point of use. Waveguide conduits can be either flexible or rigid, or have a rigid portion and a flexible portion. A waveguide conduit can have multiple functions. A primary and important function of the waveguide conduits is to give a user control of surgical access, in either a hand-held manner, known as handpiece style waveguide conduits, or by means of electromechanical actuators or robotic devices such as Flexguide™ products available from OmniGuide, Inc., based in Cambridge, Mass.
Examples of known robotic surgical systems utilizing lasers and other instruments are provided by Mohr in U.S. Patent Publication No. 2009/0171372, by Williams et al. in U.S. Patent Publication No. 2009/0248041 and by Prisco et al. in U.S. Patent Publication No. 2010/0249507, for example, all assigned to Intuitive Surgical Operations, Inc. and/or Intuitive Surgical, Inc. of Sunnyvale, Calif., which provides the Da Vinci™ robotic platform. Robotically assisted surgery through a single port utilizing an image capturing device and multiple surgical tools is described by Mohr in U.S. Pat. No. 8,517,933.
Other functional elements may include mechanical protection of the waveguide, control of waveguide bending for surgical access and control of associated optical performance variation (optical loss due to bends) of the waveguide, means for keeping the waveguide inside the waveguide conduit and optically aligned with the conduit distal tips during usage, couplers for mechanical coupling of the waveguide conduit with an external manipulator, and mechanical supports of other functional elements that may be affixed to the conduit (e.g., distal tips, suction irrigation tools, etc.). The waveguide conduit is preferably steerable in a well-controlled and precise motion manner, critical for minimally invasive surgical procedures, by means of a handle and/or attachment to a manipulator. It is preferably sterilizable and may be disposable or reusable.
Suitable materials for the waveguide conduit portions include stainless steel (e.g., 300 and 400 series surgical grade steels), titanium, aluminum, various alloys of aluminum, ceramic materials such as alumina and zirconia, and polymer materials such as silicones, polyamides, polycarbonates, PEEK, and polyolefin.
The configuration of the waveguide conduit depends on the particular application. It may vary in length and may contain several bends placed anywhere between distal (adjacent to the surgical site) and proximal ends (closer to the surgeon or other user of the device), depending on the requirements of a particular application. For example, conduits used for oral surgeries (e.g., base of tongue), are generally rigid and relatively short with fewer bends than waveguide conduits used for laryngeal work. A typical range of bend angles between distal and proximal ends is 20°-60° and total length may be from about 5 cm to about 25 cm for oral surgeries, while for laryngeal surgical procedures the bend angles maybe larger, up to 90°, and the total length may be up to about 45 cm. Yet for laparascopic procedures, even longer waveguide conduits are utilized, up to about 65 cm.
More generally, several conventional approaches are typically employed to provide a surgical tool that i) has a bend, ii) can be inserted into a trocar iii) without having to push too hard to get it through the trocar, and iv) does not deflect too much when used during surgical procedures.
In one prior approach, one may utilize an angled working feature that is limited to an overall diameter that is not larger than the inner diameter (“I.D.”) of the trocar sleeve. There is typically 1 mm clearance between the I.D. of the trocar sleeve and the outer diameter (“O.D.”) of the tool shaft, or 0.5 mm of clearance surrounding the shaft when it is centered in the trocar sleeve, though the exact clearance varies from manufacturer to manufacturer. As mentioned above, for example, 3 mm, 5 mm, and 8 mm shafts are typically used with 4 mm, 6 mm, and 9 mm trocar sleeve dimensions, respectively. This may result in a limited working angle that is achievable.
Other prior solution includes altering the angle of the working feature after insertion through the trocar sleeve, either through articulation utilizing steerable linkages or shape memory alloys. These solutions may be costly, adversely affect the robustness of the tool, and introduce cleaning and sterilization complications.
It is desirable to have surgical tools such as waveguide conduits that hold a selected bend during normal surgical use yet can be passed through trocars and other access devices.